<!DOCTYPE html>
<meta charset="utf-8">
<title>offset-anchor composition</title>
<link rel="author" title="Eric Willigers" href="mailto:ericwilligers@chromium.org">
<link rel="help" href="https://drafts.fxtf.org/motion-1/#offset-anchor-property">
<meta name="assert" content="offset-anchor supports animation.">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/support/interpolation-testcommon.js"></script>

<style>
.target {
  width: 200px;
  height: 200px;
}
</style>
<body>
<script>
test_composition({
  property: 'offset-anchor',
  underlying: '40px 60px',
  addFrom: '60px 40px',
  addTo: '160px 140px',
}, [
  {at: -0.25, expect: '75px 75px'},
  {at: 0, expect: '100px 100px'},
  {at: 0.25, expect: '125px 125px'},
  {at: 0.5, expect: '150px 150px'},
  {at: 0.75, expect: '175px 175px'},
  {at: 1, expect: '200px 200px'},
  {at: 1.25, expect: '225px 225px'},
]);

test_composition({
  property: 'offset-anchor',
  underlying: 'top 20% left 40%',
  addFrom: 'left 60% top 80%',
  addTo: 'right 80% bottom 40%',
}, [
  {at: -0.25, expect: '110% 105%'},
  {at: 0, expect: '100% 100%'},
  {at: 0.25, expect: '90% 95%'},
  {at: 0.5, expect: '80% 90%'},
  {at: 0.75, expect: '70% 85%'},
  {at: 1, expect: '60% 80%'},
  {at: 1.25, expect: '50% 75%'},
]);

test_composition({
  property: 'offset-anchor',
  underlying: '40px 60px',
  replaceFrom: '100px 200px',
  addTo: '160px 40px',
}, [
  {at: -0.25, expect: '75px 225px'},
  {at: 0, expect: '100px 200px'},
  {at: 0.25, expect: '125px 175px'},
  {at: 0.5, expect: '150px 150px'},
  {at: 0.75, expect: '175px 125px'},
  {at: 1, expect: '200px 100px'},
  {at: 1.25, expect: '225px 75px'},
]);

test_composition({
  property: 'offset-anchor',
  underlying: '40px 60px',
  addFrom: '60px 140px',
  replaceTo: '200px 100px',
}, [
  {at: -0.25, expect: '75px 225px'},
  {at: 0, expect: '100px 200px'},
  {at: 0.25, expect: '125px 175px'},
  {at: 0.5, expect: '150px 150px'},
  {at: 0.75, expect: '175px 125px'},
  {at: 1, expect: '200px 100px'},
  {at: 1.25, expect: '225px 75px'},
]);
</script>
</body>
